A simple integration problem

Hi

I need to integrate a curve with respect to time, but I dont know how to do so using COMSOL. My values representing my curve is a solution from a transient model, and is a ratio between two values hence dimensionless ([-]). A picture of the curve can be seen in the attached png-file.

I have tried "Definitions->Model Couplings->Integration" but it won't work since I'm asked to select a "Geometric entity level" which my curve dont have. I haven't had any luck using the mathematical in-built operators shown in the documentation. - or am I missing something?

I hope you can help me.
(I'm using COMSOL 4.3b)


Thanks in advance